Holster designs have evolved quickly in recent years due to safety concerns for the wearer. The first holsters were simply open pouches in which the handgun could be withdrawn in a single motion. These open pouch designs had no means of securing the handgun in the holster to prevent inadvertent or adversarial withdrawal. In response to concerns for wearer safety, holsters with a single security device were developed. Typically, the security device included a strap spanning the open holster pouch and provisionally secured to the holster with a snap. The strap prevented withdrawal of the gun until unsnapped.
A more advanced form of this single security holster design is the common thumb-break holster in which the strap is snapped to the raised inside top edge of the holster, which takes the form of a tab extending from the pouch. This allows the snap to be unfastened with the wearer's thumb to provide quick and easy access to the handgun. However, the thumb-break would also be opened just as easily by an adversary, who could simply reach in from behind the wearer, unsnap the strap and withdraw the gun from the rear.
In recent years there have been many attempts to provide additional security in thumb-break style holsters for preventing unwanted handgun withdrawal. These holster designs have typically added a second level of security which inhibits in some manner handgun withdrawal after the strap is opened. Most designs have added as a second level of security some form of holster tension to inhibit gun withdrawal. In one solution, a strap was added across the rear of the pouch opening to cover the revolver trigger guard. This prevents the gun from being withdrawn from the rear. The front of the pouch is then slit to allow the gun to be pushed forward and out and up through the front section of the holster. Typically, a spring member is sewn into the pouch surrounding the slit to provide a tension which must be overcome to withdraw the gun.
The advantage of this holster design was that the gun had to be pushed forward and up to be removed; an adversary had to be standing in front of the wearer to remove the gun, which allowed the wearer additional time to react. However, these holsters suffer from a number of drawbacks which have prevented them from being universally accepted as providing sufficient security. First, the thumb-break is the only actual positive security device. The secondary security device is simply the holster spring tension in combination with the requirement of forward gun motion. Thus, once the primary device is defected, there is a possibility of inadvertent gun withdrawal. Another drawback is the requirement of providing holster tension. Typically, holsters are leather and the tension is provided by sewing a strong spring into the pouch. However, this requires much additional expense and labor in manufacturing the holster. Also, the springs are typically quite stiff when new and must be worked in until they have enough give to allow the wearer to withdraw the gun in a comfortable fashion. As the holster is used, the spring continues to wear, providing less and less security. In relying on spring tension as the secondary device, these holsters will eventually wear and have to be replaced.
Another problem the spring tension thumb-break holsters is that the holster must typically be worn so the pouch is vertical to allow the wearer to relatively easily remove the gun with the forward and up movement required. However, the Federal Bureau of Investigation has determined after much study that a slight forward holster cant or rake of approximately thirteen degrees from vertical is the ideal holster position, primarily to ensure that the wearer leans forward into a crouching position as the gun is drawn, and also for deterring withdrawal from the rear. With the spring tension thumb-break holster, if the pouch is raked or canted forward, the forward and up removal motion becomes awkward and difficult to accomplish quickly; the forward motion would become almost a downward motion which would be clumsy and could potentially lead to situations in which the handgun could not be withdrawn quickly enough. Thus, those holsters can be worn in the safest and most secure manner.
Another problem with the spring tension thumb-break style holsters has been created by the recent tread of security forces carrying semi-automatic pistols. Typically, the semi-automatics have a flat trigger guard which can not be held in place with the trigger guard strap used in revolves holsters. One solution to this problem has been to employ a protruding member built into the holster pocket positioned to rest inside the trigger guard when the pistol is placed in the holster. The protruding member is positioned to prevent vertical or rearward withdrawal; the handgun must be pushed forward and up to withdraw, much as in the handgun holsters. However, the protruding member adds greatly to the complexity of the holster and may also be a security hazard, as it rests inside of the trigger guard. By having a protruding member adjacent the trigger, there is always the possibility that the gun could be jostled enough to press the trigger against the protruding member and fire the gun while in the holster. Thus, there exists a need for more secure double security thumb-break style holster for semi-automatic pistols.